Radiation pyrometer device



1939- L. o. SORDAHL 7 2,184,169

RADIATIOIQ PYROMETER DEVICE Filed Dec. 29, 1938 V INVENTOR Lou/s OSCAR5020/1/11.

'ATTOR EY Patented us. 19, 1939 RADIATION "BOMBER DEVICE Louisscar-SordahL Chicago, 111., assignor to Urdted States Steel Corporation,a corporation of New Jersey Application December :9. 193a. Serial No.mag:

4' Claims. (oi. 72-355) This invention relatesto pyrometer devices andmore particularly to a radiation pyrometer device adapted to measure thetemperature of molten metal baths and has for its object the provisionof an improved device for use in the measurement of the temperature ofmolten metal baths. Another object is to facilitate the obtaining of anautomatic record of the temperature of molten metal baths. Other objectsand advantages will be apparent.

Heretofore in the art it has been proposed to obtain the temperature ofa molten metal bath by means of a radiation sensitive. device located inone end of a'tubular structure through immersing the open end of thetube in the molten metal, utilizing the energy generated in theradiation sensitive device to form a visual or permanent record of thetemperature of the bath, as

indicated in Collins et al. Patent No. 2,020,092,

issued November 5. 1935.

I have found that the pyrometer device ofthe type disclosed by thisCollins et al. patent is defective and is incapable of producing anaccurv ate temperature reading for the reason that no means is providedto restrict the radiation falling upon the radiation sensitive device tothe radiation emanating from the molten-metal. In accordance with thepresent invention, this means is provided. Moreover. the device isstructurallyweak, and, as a consequence, inaccurate and misleadingtemperature measurements are obtained.

Before further disclosure of the present invention reference should bemade to the accompanying drawing, wherein:

Fig. 1 is sectional view illustrating the device of the presentinvention; Fig. 2 is an enlarged view of the same; Fig. 3 is a sideelevational v'ew of the top end of the device; Fig. 4 is a section alongplane {-3 of Fig. 1; Fig. 5 is a section along l plane 55 of Fig. 2; andFig. 6 is a perspect've view illustrating one feature of the presentinvention.

Referring to the drawing (Fig. 1), the improved pyrometer device of thepresent invention com- 3 prises an elongated tube A, preferablycomprised of metal such as iron or steel, a radiationsensi- V tive meansR closing one end of the tube, a tip means T provided with an opening 0closingthe opposite end of the tube, concentrically sustained a D innertube B. also preferably comprised of metal,

to conduct radiation passingthrough opening 0 of tip T to radiationsensitive means It, diaphragms D along the length of the. tube B torestrict radiation pmg to radiat on sensitive 5 means 3 along tube B tothat radiation traveling and ,to prevent the inflow. of molten' metal 5through opening 0 in tip T when the tip in service use is immersed in amolten metal bath.

The details of construction preferred for the device of the presentinvention may be noted from Fig. 2. Radiation sensitive means R.comprises a 19. radiation sensitive device It which is common to. theart and a lense Ii for concentrating radiation traversing tube 13thereon, the said device l0 and len'se ll being detachabLv secured inthe end of tube A transversely to the tube axisinany l5 convenientmanner, substantially as indicated, the entire assembly being covered bythe detachable cap means identified by letter R, the detachab lity. ofcap B being obtained by slot and screw arrangement I2 Means such asindicated at I3 99 for permitting terminals ll of radiation device It topass through cap R is provided. The encomprises a tubular member formingsub- Bil stantially an extension of tube A when threaded onto coupling2| threadedly engaging the end of tube A. The upper end of .tube B issustained in desired axial position relative to tube A within tubularmember 20 by means of spacermember 815 22. Preferably the tube B issustained by wedge contact of spacer member 22, substantially asindicated, to facilitate theremoval of tube B and its replacement whendesired. The arrangement shown provides for the sealing of the outer 40surface of tube B tothe inner surface of tube A at the upper end therebylimiting radation passing to radiation sensitive device to that passingthrough tube B.

'As shown in the drawing. tube B extends to adjacent the botom of tube Aand the bottom end of tube B is maintained in desired spaced relation totube A by spacer means S.

Diaphragm means D to define a light tunnel of determined cross-sectionalarea and to limit ra- 5 diation traversing tube tube B to that passingin a substantially straight line path comprises a washer 30 and splitspring members 3l-3i located'on opposite sides of washer 30 as indicatedin perspective in Fig. 6. By this arrangement-the plurality of diaphragmmeans D may be located in any desired spaced relation within tube B andthe orifice diameter of the washer 30 may be varied as may be desired.

Means C to supply a pressure of air to the interior of tube A in thearea between tubes A and B may be widely varied without departure fromthe present invention. In the arrangement provided, I have arranged forthe means to also function as a handle for workmen utilizing thedevice.As indicated in the drawing, coupling member 2| is provided withthreaded openings into which tubes 0-0 are threaded, the length of thetubes C c being sufficient to provide handles. The end of tube C isclosed as by cap 35, and the open end of tube C is connected as byflexible tubing 36 to a source of air under pressure.

In order to provide means to permit a portion of the air to pass intotube B so as to prevent particles of dust from entering tube B throughthe bottom open end, orifice 31 is provided adjacent the upper end oftube B. The upper end of tube B being closed the air entering tube Bthrough orifice 31 passes downwardly and out through the open end oftube B and thence out through orifice O in tip T.

' Tip T is provided for the dual purpose of limiting the extent to whichthe molten metal enters tube A and the area of radiating surface exposedto radiation sensitive device R. The restricted opening 0 operates toincrease the pressure of the air passing therethrough thereby permittingthe use of lower. air pressures with consequent lessening in boiling andin the oxidation of the metal by the passage of the air therethrough.The tip T is preferably made of heavy stock as indicated to obtainincreased life of the tip and to obtain greater stability in theoperation of the device, the heavy stock heating more slowly and moreuniformly when in contact with the molten metal. The manner ofattachment of tip T to the end of tube A may be varied widely withoutdeparture from the present invention.

,From the above description'and' the drawing it is believed apparentthat many modifications and departures may be made from the specificembodiment illustrated in the drawing without essentially departing fromthe nature and scope of the present invention to obtain the fulladvantages of the present invention.

- The essential advantage gained by the present invention is auniformity and accuracy of temperature determination results notobtainable by prior art devices. The central tube B operates in additionto the function hereinabove described, as .einforcemefit for tube A andprevents undue warping and bending of tube A at the high temperatures towhich it is subjected during service use. The cooling effect of the aircirculating be-' tween the two tubes A and B maintains tube B at atemperature at which it will not readily bend or sag thereby preventingtube A from warping or sagging to such a degree as will interfere withthe transmission of'radiation to the radiation sensitive means R alongthe radiation tunnel provided by tube B.

In view of the above description, all modifications and departures fromthe specific embodiment illustrated are contemplated as may fall withinthe scope of the following claims.

What I claim is:

1. In a radiation pyrometer device consisting of a tubular member, aradiation sensitive device closing one end of the tubular member andmeans to supply air under pressure within the tubular member adjacentthe said closed end, a second tubular member, means to sustain saidsecond tubular member centrally within and in spaced relation to thefirst said tubular member, means to seal the outer surface of the saidsecond tubular member to the inner surface of said first tubular memberat a point between the closed end of the first tubular member and thepoint of'air entry, a plurality of spaced diaphragm members disposedalong the'interior of the second tubular member defining a radiationtunnel of desired crosssectional area, means to permit a portion of thealr under pressure to enter said second tubular member adjacent thesealed end thereof, and a closure member for the open end of said firsttubular member, said closure member being provided with an.opening ofrestricted diameter in alignment with the center axis of said firsttubular member and the center axis of said diaphragm members in thesecond tubular member deinzilng said radiation tunnel.

na radiation pyrometer device co a tubular member having an open en a riii closed end, a radiation sensitive device located in said closed endin a position to be energized by radiation traversing said tube, andmeans to supply air under pressure within the tube adjacent the saidclosed end, means defining a radiation tunnel limiting the radiationfalling on said radiation sensitive device to radiation traversing a.substantially straight line path through the tube, said means comprisinga second tubular member, means tosustain said second tubular memberconcentrically within and in spaced relation to the first tubularmember, said means sealing the two said tubular members together at apoint between the closed end and the point of air entry, a plurality ofdiaphragm members-disposed within said second tubular member indetermined and desired spaced relation defining a radiation tunnel ofrestricted cross-sectional area,-

and a closure member for the open end of said first tubular member. anopening in said closure member, said opening having a diameterapproximating the diameter of said radiation tunnel and being located insubstantial axial alignment with,

said radiation tunnel.

3. A radiation pyrometer device comprising in combination -two tubularmembers, means to sustain one tubular member centrally within and inspaced relation to the other tubular member with the outer surface ofthe inner tubular member sealed to the inner surface of the outertubular member adjacent one end, a radiation sensitive device, means tosustain said radiation sensitive device in closure position on thesealed ends of said tubular members in a position to be energized byradiation traversing the length of the inner tubular member, means tosupply a pressure of air to the space between said tubular membersadjacent the sealed ends, means to permit a portion of the air to enterthe inner tubular member adjacent the sealed end thereof, a closuremember for the open end of the outer tubular member, an opening in saidclosure member, the axis of said opening coinciding with the axis of theinner tubular member, and a plurality of diaphragm members disposed inspaced relation within the inner tubular member defining a radiationtunnel of determined cross-section leading to said radiation sensitivedevice.

4. A radiation pyrometer device comprising in combination two tubularmembers, one sustained concentrically within and spaced from the other,

means adjacent one and sealing the space gap between said tubularmembers, a radiation sensitive device, means to sustain said radiationsensitive device in closure position on the open end of the innertubular member adjacent the said sealed ends, means to supply a pressureof air to the space between said concentric tubular members, means topermit a portion of said air to enter the inner said tubular memberadjacent the closed end thereof, a closure member for the open end ofthe outer tubular member. an opening in said closure member in alignmentwith the axis of the inner tubular member, and means defining an axiallylocated radiation tunnel of tive device in asubstantially straightlinepath.

LOUIS OSCAR SORDAHL.

